1. Field of the Invention
The present invention relates to an information record medium such as an optical disk of a high recording density type, which is capable of recording information such as video information, audio information and the like at a high density, and which is represented by a DVD (Digital Video or Versatile Disk). The present invention also relates to a recording apparatus for recording the information onto the information record medium, and a reproducing apparatus for reproducing the information from the information record medium.
2. Description of the Related Art
Conventionally, a so-called LD (Laser Disk) and a so-called CD (Compact Disk) are generalized as optical disks, on which information such as video information, audio information and the like is recorded.
On the LD, the CD or the like, the video information and the audio information are recorded together with time information indicating a time at which each information is to be reproduced with respect to a reproduction start position, which each LD or the like has, as a standard position. Thus, other than a general normal reproduction to reproduce the recorded information in the order of recording various special reproductions are possible, such as a reproduction to extract and listen to an only desirable music out of a plurality of recorded musics, a reproduction to listen to the recorded musics in a random order and so on, in case of the CD, for example.
However, there is a problem that, according to the above mentioned CD, LD or the like, a so-called interactive and variegated reproduction is not possible in which the audience can have a plurality of selection branches as for the video or audio information to be displayed or sound-outputted and in which the audience can select them to watch or listen to it.
Namely, for example, in case of giving audience to a foreign movie on the LD, it is not possible to select one of languages to be used for a subtitle (caption) displayed on the picture plane (e.g., select one of the subtitle in Japanese and the subtitle in the original language) so as to display the subtitle in the selected language, or, in case of giving audience to a music recorded on the CD, it is not possible to select one of sound voices of the music (e.g., select one of the English lyric and the Japanese lyric).
On the other hand, various proposals and developments are being made as for the DVD, as an optical disk in which the memory capacity is improved by about ten times without changing the size of the optical disk itself as compared with the aforementioned conventional CD. According to the knowledge of the present inventors, it is anticipated that it is possible, as for the DVD having such a large memory capacity, to: divide audio information, video information or the like by an appropriate length respectively into an audio pack, a video pack or the like; add additional information such as header information to each pack; switch and multiplex these packs; and reproduced the multiplexed audio information, video information or the like.
However, in the field of the audio or video related technique, the audio information, the video information or the like is generally treated in a relatively large unit e.g. a so-called audio frame or video frame, at the time of recording, editing and reproducing by the recording apparatus and the reproducing apparatus. Thus, for example, assuming that the frequency of this audio frame is 75 Hz, which is the same as the case of CD, the compatibility in frequency of the audio frame is generally bad with the audio pack, the video pack or the like multiplexed in the aforementioned DVD. This results in that a very complicated reproduction method is estimated to be necessary. Further, in the technical art of the DVD, the actuality is such that a person having an ordinary skill in this art does not even recognize the subject or problem itself that the compatibility in frequency of the audio frame used in the conventional CD etc. is bad with the audio pack etc. which is expected to be usable in the aforementioned DVD.
It is therefore an object of the present invention to provide an information record medium, on which the audio information, which is to he recorded, edited and reproduced by the unit of audio frame, is recorded in a form of being divided by an appropriate length and multiplexed, can be relatively easily recorded, edited and reproduced, and also provide an apparatus for recording the same and an apparatus for reproducing the same.
The above object of the present invention can be achieved by an information record medium having a record track to be reproduced by an information reproducing apparatus, which is provided with a read device and reproduces audio information by a predetermined audio frame unit while relatively moving the read device along the record track recorded with at least the audio information by the audio frame unit. In the information record medium of the present invention, a plurality of audio packets are arranged along the record track, in each of which audio information pieces constructing the audio information sampled by a predetermined sampling frequency and audio control information for controlling a reproduction of the audio information pieces by the information reproducing apparatus are respectively recorded. The audio control information is provided with time management information for specifying a time, by a predetermined specification frequency, to manage a timing of outputting the audio information, which is included in the audio frame which head is positioned in the audio packet including the audio control information, in the reproduction by the information reproducing apparatus. And that, a frequency of the audio frame and a frequency of the audio packet are prescribed such that the frequency of the audio frame is 1/n (n: natural number) of the sampling frequency and 1/m (m: natural number) of the specification frequency, and a data amount of the audio information included in one audio packet is more than a data amount of one audio frame.
According to the information record medium of the present invention, in each of the audio packets arranged along the record the audio information pieces constructing the audio information sampled by a predetermined sampling frequency and the audio control information are respectively recorded. The audio control information is provided with time management information. The time management information specifies a time, by a predetermined specification frequency, to manage a timing of outputting the audio information, which is included in the audio frame which head is positioned in the audio packet including the pertinent audio control information, in the reproduction. At this time, since the frequency of the audio frame is 1/n of the sampling frequency, it is possible to avoid a case where the audio frame is cut in the middle of sampling. Further, since the frequency of the audio frame is 1/m of the specification frequency, the accuracy of the time specified by the time management information can be kept high. Furthermore, since the data amount of the audio information included in one audio packet is more than the data amount of one audio frame, every one of the audio packets can include the time management information respectively. As a result, such a problem is never caused that, because the time management information randomly exists or not exists in the audio packet, the recording position of the information after the time management information is shifted in a random or unknown manner. For example, it is possible to cut reading one portion of the audio control information, which is not shifted, of the bytes in the constant number in the audio packet, and to speedily read another portion of the audio control information, which is necessary for the reproduction, by use of a rather simple algorithm.
Accordingly, the construction of the information recording apparatus or the information reproducing apparatus for the DVD etc., can be simplified, and the production cost thereof can be reduced.
In one aspect of the information record medium of the present invention, the information record medium has the record track to be reproduced by the information reproducing apparatus, which reproduces video information by a predetermined video frame unit in addition to the audio information while relatively moving the read device along the record track recorded with at least the video information by the video frame unit in addition to the audio information. In this aspect, a plurality of video packets are multiplexed with the audio packets and arranged along the record track, in each of which video information pieces constructing the video information and video control information for controlling a reproduction of the video information pieces by the information reproducing apparatus are respectively recorded. And that, the frequency of the audio frame and a frequency of the video frame are prescribed such that the frequency of the audio frame is equal to an integer multiple of the frequency of the video frame.
According to this aspect, the video packets are multiplexed with the audio packets, and arranged along the record track. In each of the video packets, the video information pieces constructing the video information and the video control information are respectively recorded. At this time, since the frequency of the audio frame is equal to an integer multiple of the frequency of the video frame, it is possible to synchronize the video information and the video information. Accordingly, a complicated signal process for compensating the difference in the time between the audio information and the video information is not necessary at the time of a signal process such as a recording process, an editing process, a reproducing process and the like. Therefore, the meaning of xe2x80x9cequal to the integer multiple of the frequencyxe2x80x9d here is that the frequencies are equal to each other in such a degree that these two kinds of audio frame and the video frame can be synchronized with each other by the actual reproducing apparatus, and that the degree of the equality thereof is determined suitably in dependence upon the ability of the reproducing apparatus and the property of the signal which are actually used.
Accordingly, the construction of the information recording apparatus or the information reproducing apparatus for the DVD etc. in which the video information as well as the audio information is dealt with, can be simplified, and the production cost thereof can be reduced.
In this aspect, there may be a plurality of different kinds of frequencies as the frequency of the video frame, and the frequency of the audio frame may be preferably prescribed to be equal to a least common multiple of the different kinds of frequencies.
According to this aspect, since the frequency of the audio frame is equal to a least common multiple of the different kinds of frequencies, the audio information and the video information can be substantially synchronized with each other, as for a plurality of different types of video information such as the information based on the NTSC method, the PAL (SECOM) method, the Hi vision method or the like for example, so that it is advantageous at the time of recording, editing and reproducing.
Accordingly, the construction of the information recording apparatus or the information reproducing apparatus for the DVD etc, in which the video information based on the NTSC method, the PAL method or the like, as well as the audio information is dealt with, can be simplified, and the production cost thereof can be reduced.
In another aspect of the information record medium of the present invention, the frequency of the audio frame is 600 Hz, 750 Hz, 1200 Hz, 1500 Hz, 3000 Hz or 6000 Hz.
Accord to this aspect, since the frequency of the audio frame is one of 600 Hz, 750 Hz, 1200 Hz, 1500 Hz, 3000 Hz or 6000 Hz, in case of recording the PCM linear audio data as the audio information into the audio packet, every one of the audio packets can include the time management information respectively. Further, the audio information and the video information can be synchronized with each other, as for the video information based on the NTSC method, the PAL method or the Hi-Vision method, so that it is advantageous at the time of recording, editing and reproducing.
Accordingly, the construction of the information recording apparatus or the information reproducing apparatus for the DVD etc. in which the video information based on the NTSC method, the PAL type or the like, as well as the audio information is dealt with, can be simplified, and the production cost thereof can he reduced.
The above object of the present invention can be also achieved by an information recording apparatus for recording information onto the above described information record medium of the present invention. The information recording apparatus is provided with: a record device for respectively recording, into a plurality of audio packets arranged along the record track, audio information pieces constructing the audio information sampled by a predetermined sampling frequency and audio control information for controlling a reproduction of the audio information pieces by the information reproducing apparatus, the audio control information is provided with time management information for specifying a time, by a predetermined specification frequency, to manage a timing of outputting the audio information, which is included in the audio frame which head is positioned in the audio packet including the audio control information, in the reproduction by the information reproducing apparatus; and an input device for inputting at least one portion of the audio control information. And that, a frequency of the audio frame and a frequency of the audio packet being prescribed such that the frequency of the audio frame is 1/n (n: natural number) of the sampling frequency and 1/m (m: natural number) (of the specification frequency, and a data amount of the audio information included in one audio packet is more than a data amount of one audio frame.
According to the information recording apparatus of the present invention, the audio information pieces constructing the audio information sampled by a predetermined sampling frequency are respectively recorded into a plurality of audio packets arranged along the record track, by the record device. Along with this, as at least one portion of the audio control information provided with the time management information is inputted by the input device, the audio control information is recorded into each of the audio packets, by the record device. The time management information specifies a time, by a predetermined specification frequency, to manage a timing of outputting the audio information, which is included in the audio frame which head is positioned in the pertinent audio packet including the audio control information, in the reproduction. At this time, since the frequency of the audio frame is 1/n of the sampling frequency and 1/m of the specification frequency, and since the data amount of the audio information included in one audio packet is more than the data amount of one audio frame, the above described information record medium of the present invention can be recorded and obtained.
In one aspect of the information recording apparatus of the present invention, the information recording apparatus records onto the above described one aspect of the information record medium of the present invention. In this aspect, the record device respectively records, into a plurality of video packets multiplexed with the audio packets and arranged along the record track, video information pieces constructing the video information and video control information for controlling a reproduction of the video information pieces by the information reproducing apparatus. And that, the frequency of the audio frame and a frequency of the video frame are prescribed such that the frequency of the audio frame is equal to an integer multiple of the frequency of the video frame.
According to this aspect, the video information pieces constructing the video information and the video control information are respectively recorded into a plurality of video packets multiplexed with the audio packets and arranged along the record track, by the record device. At this time, since the frequency of the audio frame is equal to an integer multiple of the frequency of the video frame, the above described one aspect of the information record medium of the present invention can be recorded and obtained.
The above object of the present invention can be also achieved by an information reproducing apparatus for reproducing information from the above described information record medium of the present invention. The information reproducing apparatus is provided with: a read device for reading information recorded at a predetermined reading position on the record track; a movement device for relatively moving the read device along the record track; an extract device for extracting the audio packet from the information read by the read device; and an audio decode device for decoding the audio information included in the extracted audio packet by the audio frame unit on the basis of the time specified by the time management information included in the extracted audio packet.
According to the information reproducing apparatus of the present invention, while the read device is relatively moved along the record track by the movement device, the information recorded at a predetermined reading position on the record track is read by the read device. Then, the audio packet is extracted from the information read by the read device, by the extract device. Finally, the audio information included in the extracted audio packet is decoded by the audio frame unit on the basis of the time specified by the time management information included in the extracted audio packet, by the audio decode device. Therefore, it is possible to easily reproduce the above described information record medium of the present invention.
In one aspect of the information reproducing apparatus of the present invention, the information reproduction apparatus reproduces the information from the above described one aspect of the information record medium of the present invention. In this aspect, the extract device extracts the audio packet and the video packet separately from the information read by the read device. And that, the information reproducing apparatus is further provided with a video decode device for decoding the video information (included in the extracted video packet by the video frame unit.
According to this aspect, the audio packet and the video packet are separately extracted from the information read by the read device, by the extract device. Then, the video information included in the extracted video packet is decoded by the video frame unit, by the video decode device. Therefore, it is possible to easily reproduce the above described one aspect of the information record medium of the present invention.
In another aspect of the information reproducing apparatus of the present invention, the audio decode device decodes the audio information while cutting one portion of the audio control information other than the time management information included in the extracted audio packet.
According to this aspect, the audio information is decoded while cutting one portion of the audio control information other than the time management information included in the extracted audio packet, by the audio decode device. At this time, since every one of the audio packets includes the time management information respectively, and since the recording position of the information after the time management information is not shifted due to the existence and non existence of the time management information, this process of cutting one portion of the audio control information can be performed by use of a relatively simple algorithm.
Accordingly the construction of the information reproducing apparatus for the DVD etc., can be simplified, and the production cost thereof can be reduced.